| 主权项 |
1. A tip for use in an optical detection system to analyze an analyte in a fluid sample drawn into the tip, using light reflected from a detection surface inside the tip that the analyte binds to, comprising a first detection surface and a second detection surface located in a same flow path with no controllable valve separating them, wherein the first and second detection surfaces have different surface chemistries, and wherein the second detection surface has a surface chemistry that blocks it from binding to a ligand that binds to the analyte, while the first detection surface has a surface chemistry that allows it to bind to the ligand, wherein said surface chemistry of said first detection surface comprises a capturing agent selected from the group consisting of avidin, an avidin derivative, protein A, protein G, a secondary antibody and Ni(II) activated complexes of nitrilo triacetic acid, or comprises a functional group comprising one or more of active carboxylic ester, epoxide, aldehyde, and acrylate , hydroxyl, alkyl ester, carboxylic acid, sulfate, sulfonate and phosphonate, such that said analyte binds to said detection surface by binding to a ligand that binds to said surface chemistry, and
wherein said first detection surface has said capturing agent, and wherein said second detection surface, does not comprise a capturing agent for affinity-based binding of the ligand. |
